package svc // import "github.com/getwtxt/getwtxt/svc" import ( "bytes" "html/template" "io/ioutil" "os" "sync" "time" ) // These functions and types pertain to the // in-memory data being used by the registry // service, such as: // - static assets (index.html, style.css) // - the registry itself (users, etc) // - list of other registries submitted // RemoteRegistries holds a list of remote registries to // periodically scrape for new users. The remote registries // must have been added via POST like a user. type RemoteRegistries struct { Mu sync.RWMutex List []string } // staticAssets holda the rendered landing page // as a byte slice, its on-disk mod time, the // assets/style.css file as a byte slice, and // its on-disk mod time. type staticAssets struct { mu sync.RWMutex index []byte indexMod time.Time css []byte cssMod time.Time } // Renders the landing page template using // the info supplied in the configuration // file's "Instance" section. func initTemplates() *template.Template { confObj.Mu.RLock() assetsDir := confObj.AssetsDir confObj.Mu.RUnlock() return template.Must(template.ParseFiles(assetsDir + "/tmpl/index.html")) } func cacheUpdate() { // This clusterfuck of mutex read locks is // necessary to avoid deadlock. This mess // also avoids a panic that would occur // should twtxtCache be written to during // this loop. twtxtCache.Mu.RLock() for k := range twtxtCache.Users { twtxtCache.Mu.RUnlock() errLog("", twtxtCache.UpdateUser(k)) twtxtCache.Mu.RLock() } twtxtCache.Mu.RUnlock() remoteRegistries.Mu.RLock() for _, v := range remoteRegistries.List { errLog("Error refreshing local copy of remote registry data: ", twtxtCache.CrawlRemoteRegistry(v)) } remoteRegistries.Mu.RUnlock() } // pingAssets checks if the local static assets // need to be re-cached. If they do, they are // pulled back into memory from disk. func pingAssets() { confObj.Mu.RLock() assetsDir := confObj.AssetsDir confObj.Mu.RUnlock() cssStat, err := os.Stat(assetsDir + "/style.css") errLog("", err) indexStat, err := os.Stat(assetsDir + "/tmpl/index.html") errLog("", err) staticCache.mu.RLock() indexMod := staticCache.indexMod cssMod := staticCache.cssMod staticCache.mu.RUnlock() if !indexMod.Equal(indexStat.ModTime()) { tmpls = initTemplates() var b []byte buf := bytes.NewBuffer(b) confObj.Mu.RLock() errLog("", tmpls.ExecuteTemplate(buf, "index.html", confObj.Instance)) confObj.Mu.RUnlock() staticCache.mu.Lock() staticCache.index = buf.Bytes() staticCache.indexMod = indexStat.ModTime() staticCache.mu.Unlock() } if !cssMod.Equal(cssStat.ModTime()) { css, err := ioutil.ReadFile(assetsDir + "/style.css") errLog("", err) staticCache.mu.Lock() staticCache.css = css staticCache.cssMod = cssStat.ModTime() staticCache.mu.Unlock() } }